Propeller



C. H. CASPAR.

PROPELLER.

APPLICATION FILED OCT. 22, 1.918..

Patented Mar. 8, 1921.

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UNITED. STATES PATEnTIoF FICE.

CHARLES H, OASPAR, OF PHILADELPHIA, PENNSYLVANIA,

rnornnmn.

Specification of Letters Patent.

Patented Mar. 8, 1921.

Application iiled October 22, 1918. Serial No. 259,189. I

To all whom it may concern:

Be it known that 1, CHARLES a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Propellers, of which the following is a specification.

My invention relates to prope llers for H. CAsrAiz,

aeroplanes; and one object of my invention is to provide means whereby Ifcan obta1n,*

automatically, variable area in the sweep of the propeller blades. A further object of automatically, variable pitch of the blades.

These and other features of my invention are more fully described hereinafter, reference being had to the accompanying drawin s, in which:

igure 1, is a view in elevation of a protion. Y

Fig. 2, is an enlarged sectional viewof I: the hub of the propeller.

blades are connected F ig. 3, is a sectional View on the line 11141 13, Fig. 1.

Figs. 4 and 5, are sectional views on the lines IV-IV and V-V, Fig. 2, respectively, and

Fig. 6, is a sectional view similar to Fig. I

2, illustrating a modified construction within the sec e of my invention.

In the rawings, 1 represents the hub of my improved propeller; 2 and 2 the blades, and 3 the shaft on which such hub is mounted. This hub may be provided with a stream-line projection 4, forwardly disposed, although this feature may be omitted without departing from my invention.

The blades 2, 2' may be provided adjacent their point of connection with the hub with so-called holders or sockets 5, 5*, each having an arbor 6, 6 by means of which said to and journaled in screw plugs 7 and 7; such arbors being held in position by nuts 8 and 8*. The screw plugs 7, 7* are provided with so-called cap portions 9, 9 between which and the rim portion 10, 10 of the propeller sockets a space 11, 11 is formed, and within the spaces so provided, tension springs 12,12 may be mounted.

' The rim of each propeller socket is provided with a projection 13, 13, and each is mounted. The projections 14, 14 may peller made in accordance with my inveneach be provided with tension adjusting means in the shape of a bolt 15 threaded into each of said projectiohs 14, 14 andhaving a lock nut 16 wherebv said bolt may be secured when properly adjusted. The projections 13, 13 of the blade socket, when the blade is in its normal position, preferably engage elastic'bufi'ers 17 mounted on 'projections 18, also carried by the cap portion of the screw plug.

The respective screw plugs 7 and 7 are connected to telescopic sleeves l9 and 19*, the walls of which are slotted at 20 and'20 respectively, and the hub carries a centrally disposed pin 21, to which sets of springs 22 and 22 are centrally anchored; the opposite ends of said springs being connected to pins 23 and 23 carried by'the telescopic sleeves l9 and 19 respectively. By preference, the several pins carry saddles 24, over which the ends of the springs are hooked.

The sleeve 19 may be provided with stop 1 the sleeve 19* to limit the inward movement of the same effected by the springs 22, and the sleeve 19 may be equipped with stop pins 25 performing a similar functionwith res ect to the sleeve 19.

s may be readily understood centrifugal action, when the blades are rotating, will tend to throw the same outwardly, overcoming the tension of the springs 22 and 22% which will be elongated bysuch action, so that under the higher speeds the sweep of the blades will be materially increased. As the speed of rotation decreases, the ten- ,.sion of the springs will carry the blades inwardly toward their normal. position. The l1igher speeds tend to lessen. the air resistance with the surfaces of the blades in their normal position, and for this-reason means are provided, such as the pivotal connection with the sleeves 19 and 19, which permit the blades to turn with respect to the hub; such movement, being resisted to a certain extent by the springs 12, so that when lower speed is resumed, the blades will be automatically restored to their normal position with respect to the hub.

The slots in the sleeves 19 and 19 are ios straight, so that outward movement of the with the centrally disposed pin 21, which passes through the hub and for which the sleeves are slotted to permit movement of the same with respect thereto.

I claim: v 1. The combination, in a propeller, of a plurality of blades, mutually, telescopic sleeves connected to the ends of said blades, tension means for each blade tending to hold said sleeves together, and a common anchorage for the inner ends of said tension means, such tension means being, elongated when the blades revolve and move outwardly under centrifugal force.

2. The combination, in a propeller, of a hub, a plurality of blades, mutually telescopic sleeves mounted in said hub and connected to the ends of said blades; saidsleeves being longitudinally movable in the hub, means preventing dislodgment of the sleeves with respect to the hub, tension means tending to hold said sleeves to.- gether and an anchorage for the tension means centrally located with respect to said hub, such tension means being elongated when the blades revolve and move outwardly under centrifugal force.

3. The combination, ina propeller, of a plurality of blades, -mutually telescopic sleeves connected to the ends of said blades,

pivotal connections between said blades and sleeves permitting rotative movement therebetween, tension means located within the inner sleeve and tending to hold said sleeves together; such tension means being elongated when the blades revolve andcarry outwardly under centrifugal force, and

means for anchoring the tension means to the hub and to therespective sleeves; said and sleeves permitting rotative movement therebetween, tension means tending to hold said sleeves in the inward position with respect to the hub; such tension means being elongated when the blades revolve and carry outwardly under centrifugal force, and means for resisting the turning movement of the blades with respect to the sleeves.

5. The combination, in a propeller, of a pair of blades, telescopic sleeves carried by the inner ends of said blades, pivotal connections between said blades and sleeves and tension means surrounding said pivotal connections between said sleeves and blades permitting changes in the pitch of said blades.

6. The combination, in a propeller, of a hub, telescopic sleeves carried by the inner ends of said blades and mounted insaid hub, blades carried by said sleeves, pivotal CHARLES H. CASPAR.

in the pitch of said, 

